Valve stem assembly for rotary valve and method

ABSTRACT

A valve body defines a valve stem opening. A valve stem comprises an enlarged portion greater than the valve stem opening to thereby secure the valve stem within the valve body by limiting radially outward movement of the valve stem with respect to the valve body. A rotary member comprise upper and lower bosses. Upper and lower split trunnions, with split components that can be inserted from opposite sides of the valve body, are used to rotationally support the upper and lower bosses to permit rotation of the rotary member while preventing axial movement of the axial flow path of the valve.

This application claims benefit of U.S. Provisional Application No. 61/319,342 filed Mar. 31, 2010, U.S. Provisional Application No. 61/333,517 filed May 11, 2010 and U.S. patent application Ser. No. 12/835,071 filed Jul. 13, 2010. All of the above applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to rotary valves and, more particularly, to an improved valve stem assembly.

2. Description of the Background

Larger diameter rotary valves, such as ball valves and plug valves, may typically utilize trunnions to secure the rotary element within the valve body. In other words, the rotary element is trunnion mounted. As an alternative to trunnion mounting of the rotary element, smaller valves may allow the rotary element to float within the valve body. In these smaller valves, an enlarged end may then be provided on the valve stem to retain the valve stem within the valve body. The enlarged end of the valve stem secures the valve stem in the valve body making the stem virtually blow out proof. However, for trunnion mounted rotary elements, the enlarged end cannot be used because the valve stem and rotary element cannot be inserted into the body due to the presence of the trunnions.

Therefore, in valves used in the last several decades, the trunnion mounted rotary elements utilize an external plate to secure the valve stem to the valve body. The plate is bolted onto the valve body. The valve stem may then have an enlarged end, which is larger than the opening in the plate bolted onto the valve but is not larger than the opening in the rotary valve through which the stem is used to engage and rotate the rotary element.

However in this type of valve, which has been used for decades, forces produced by the actuator by repeatedly opening and closing the valves may cause the bolts holding the plate to the body to fatigue whereupon there is a potential that the valve stem may be released from the valve when the valve is under pressure.

The prior art discussed above does not show a design that does not rely on body bolting or fasteners of any kind to retain the valve stem within the pressure area of a valve with a trunnion mounted rotary element. Those of skill in the art will appreciate the present invention that addresses the above needs and other significant needs, the solution to which are discussed hereinafter.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved rotary valve.

Another object of the present invention is to provide a blowout proof valve stem, while using a trunnion mounted rotary element.

Yet another object of the present invention is to provide a valve body retained valve stem wherein the rotary element is trunnion mounted.

These and other objects, features, and advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims. However, it will be understood that the above-listed objectives and/or advantages of the invention are intended only as an aid in quickly understanding aspects of the invention, are not intended to limit the invention in any way, and therefore do not form a comprehensive or restrictive list of objectives, and/or features, and/or advantages.

Accordingly, the present invention provides a rotary valve, which comprises a valve body, which defines a valve stem opening. The valve stem comprises an enlarged portion with a maximum diameter greater than the inner diameter of the valve stem opening, which thereby secures the valve stem within the valve body by limiting radially outward movement of the valve stem with respect to the valve body. A first set of split support elements comprises at least two separable sections which are mountable within the valve body from opposite sides of the valve body. When mounted within the valve body, the first set of split support elements may define a first opening therethrough.

In one embodiment, a rotary member has a first extension positioned within the first opening defined within the first set of split support elements whereby the first extension is rotatable within the first opening. The first extension is interconnectable with the valve stem within the valve body, whereby the rotary member rotates in response to rotation of the valve stem.

In one embodiment, the rotary valve may further comprise a second set of split support elements with at least two separable sections which are mountable within the valve body from opposite sides of the valve body.

When mounted within the valve body the second set of split support elements may in another possible embodiment define a second opening therethrough. In this embodiment, a second extension on the rotary member is positioned on an opposite side of the rotary member from the first extension. The second extension is positioned within the second opening defined within the first set of split support elements whereby the first extension is rotatable within the second opening.

The rotary valve may further comprise a first bearing mounted in the first opening around the first extension and a second bearing mounted in the second opening around the second extension.

The rotary valve further comprises a first end connector mountable to the valve body and a second end connector mountable to the valve body opposite to the first section. The first end connector and the second end connector secure the split support elements together within the valve body.

In one embodiment, the rotary member is ball shaped. In one embodiment, the first extension is cylindrical.

The rotary valve may further comprise a stem thrust washer mounted on the enlarged end of the valve stem which engages an inner surface of the valve body.

In another embodiment, a method for making a rotary valve comprises steps such as inserting a valve stem through an opening in a valve body and utilizing an enlarged portion of the valve stem which does not pass through the opening to retain the valve stem within the valve body.

Other steps may comprise inserting a rotary element into the valve body, whereby an upper extension of the rotary element engages the valve stem, and supporting a first extension on the rotary valve for rotational movement by inserting a first set of split support elements from opposite ends of the valve body.

The method may also comprise supporting a second extension on the rotary valve for rotational movement by inserting a second set of split support elements from opposite ends of the valve body. In this case, the method may comprise utilizing a first end connector and a second end connector for securing the first set of split support elements and the second set of split support elements within the valve body. The method may comprise positioning a first bearing around the first extension and positioning a second bearing around the second extension.

In one embodiment, the method may comprise positioning a thrust washer on the enlarged end of the valve stem to engage an inner surface of the valve body.

In one embodiment, the method may comprise providing that the first set of split support elements define a first opening which receives the first extension.

In another possible embodiment, the rotary valve, may comprise a valve body, which defines a valve stem opening, a valve stem with an enlarged portion greater than the valve stem opening to thereby secure the valve stem. A rotary member may comprise a first portion at one side thereof. A first set of split support elements may comprise at least two separable sections which are mountable within the valve body from opposite sides of the valve body. The first set of split support elements constrain the first portion of the rotary member for rotational movement. The rotary member is interconnectable with the valve stem within the valve body, whereby the rotary member rotates in response to rotation of the valve stem. The rotary member comprises a second portion at a second side of the rotary member opposite to the first side.

In one embodiment, a second set of split support elements may comprise at least two separable sections which are mountable within the valve body from opposite sides of the valve body. Once mounted within the valve body, the second set of split support elements constrain the first portion of the rotary member for rotational movement and prevent axial movement along the axis of the flow path through the valve.

In one embodiment, the first portion of the rotary member comprises a first cylindrical extension and the second portion of the rotary member comprises a second cylindrical extension.

In another embodiment, a rotary valve may comprise a valve body, which defines a valve stem opening, and a valve stem with an enlarged portion relative to the valve stem opening to thereby secure the valve stem within the valve body.

The rotary member may comprise upper and lower bosses. Upper and lower split trunnions may be utilized to rotationally support the upper and lower bosses for rotation of the rotary member.

The rotary valve may further comprise upper and lower trunnion bearings around the upper and lower bosses.

In another embodiment, a method for making a rotary valve may comprise inserting a valve stem through an opening in a valve body whereby the opening retains a relatively enlarged portion of the valve stem within the valve body.

Other steps may comprise inserting a rotary element into the valve body whereby an upper boss engages the valve stem, which may be enlarged portion of the valve stem.

Additionally, the method may comprise supporting upper and lower bosses on the rotary valve by inserting upper and lower split trunnion elements from opposite ends of the valve body.

BRIEF DESCRIPTION OF THE DRAWING

Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawing, and wherein:

FIG. 1 is an exploded view, in perspective, showing a rotary valve with body retained valve stem and split trunnions in accord with one possible embodiment of the present invention; and

FIG. 2 is a perspective view, partially in section, showing the rotary valve of FIG. 1 in accord with one possible embodiment of the present invention.

While the present invention will be described in connection with presently preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents included within the spirit of the invention and as defined in the appended claims.

DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

Referring now to the drawings, and more particularly to FIG. 1 and FIG. 2, the present invention teaches rotary valve 10, in this case a ball valve, which provides a body retained valve stem 16 within valve body 12.

Valve body 12 defines valve stem opening 14 therein. In one embodiment, valve stem opening 14 is a straight-sided cylindrical opening. However, valve stem opening 14 could also have other configurations. Valve stem 16 may comprise cylindrical elongate body 18 with enlarged portion 20 at one end thereof, which may also be cylindrically shaped. Enlarged portion 20 is greater in diameter than valve stem opening 14 and is therefore retained within valve body 12 with the full strength of wall 24 of valve body 12, and without the need for reliance on bolts or fasteners.

Enlarged portion 20 may be formed in different ways and, in this embodiment, can comprise any enlarged component or portion of valve stem 16 which directly or indirectly engages an interior surface of valve body wall 24 or an interior portion of valve stem opening 14 to limit radially outward movement of valve stem 16 and retain valve stem 16 within valve body 12. As a different example, enlarged end 20 might comprise a thrust bearing or the like which is enlarged with respect to valve stem opening 14.

In another example, valve stem 16 might comprise a conical or tapered portion which engages a conical or tapered portion of valve stem opening 14. Thus, valve stem opening 14 and valve stem 16 are designed with any suitable proportions such that valve stem 16 has a portion which has a larger diameter than at least a portion of valve stem opening 14 so that valve stem 16 is retained within valve body 12.

During assembly of this embodiment, cylindrical elongate end 18 of valve stem 16 is inserted into the interior side of valve stem opening 14 in valve body 12. Enlarged end 20 is then positioned within body interior 22 of valve body 12 whereby the interior surface of valve body 12 prevents further radially outwardly movement of valve stem 16. In this way, the thickness of wall 24 of valve body 12 securely retains valve stem 16 within valve body 12, making a blowout proof, body-retained valve stem 16. Prior to insertion through valve stem opening 14, seals, bearings, and the like may be utilized on valve stem 16. While there are many possible arrangement of such elements, in this embodiment, stem thrust washer 68, upper stem seal 70, and O-ring stem seals 73 are utilized. Stem thrust washer 68 then engages the interior surface of wall 24 of valve body 12.

In this embodiment, to enable assembly of a trunnion mounted rotary valve 10 with body retained valve stem 16, split upper and lower trunnions 26 and 28 are utilized. The split trunnions comprise separate components 26 a, 26 b, and 28 a, 28 b that can be inserted from opposite sides of valve body 12.

Depending on the design of the components, lower trunnion 28 may not need to be split, if desired, due to the absence of the need for a valve stem on the lower side. However, at least upper trunnion 26 is preferably split so that upper trunnion 26 can be inserted into valve body 12 after the rotary element 30 is inserted into valve body 12, and after valve stem 16 is inserted into the valve body.

As used herein, a trunnion is a support element, which is used to support the upper and lower portions of rotary element 30 in valve body 12 for constraining movement of rotary element 30 to rotational movement without axial movement along the axis of flow path 42 through rotary valve 12. In other words, rotary element 30 does not “float” along the axis of the flow path as in other types of rotary valves discussed hereinbefore. Thus, the term “support element” or “split support element” may also be utilized to refer to upper and/or lower trunnions 26 and 28. The trunnions engage upper and lower portions of rotary element 30, which may be of various shapes and which may or may not comprise extensions or protuberances of rotary element 30.

In this embodiment, upper and lower split trunnions 26 and 28 are provided to secure or support upper and lower bosses 32 and 34. Upper and lower bosses 32 and 34 can be but are not required to be protuberant parts or extensions on the upper and lower sides of rotary element 30. In this embodiment, upper and lower bosses 32 and 34 comprise cylindrically shaped extensions with a substantially constant diameter over their length.

However, the diameter of upper and lower bosses 32 and 34 is not required to be constant, nor is the protuberance or extension required to be straight-sided. For instance, the extension could be rounded where upper boss 32 now appears to comprise a straight sided cylinder. As another example, the upper and lower bosses may comprise an upper portion of the surface of rotary element 30 without an extension.

Essentially, upper and lower bosses 32 and 34 are mounting support regions on rotary element 30 which are supported by the upper and lower trunnions so as to be constrained to rotational movement without axial movement along axial flow path 42. This contrasts with the floating rotational element of other rotary valves. Upper and lower bosses 32 and 34 need not be extensions but may comprise any possible type of pivot region for rotary element 30 to be supported for or constrained to rotational movement of rotary element 30 while preventing axial movement along axial flow path 42.

In this embodiment, upper and lower trunnions 26 and 28 define upper and lower mating cylindrical openings 36 and 38 that support upper and lower bosses 32 and 34 for rotary movement of rotary element 30 within valve body 12 to open and close rotary valve 10. The openings or engagement surfaces formed on upper and lower trunnions 26 and 28 mate to upper and lower bosses 32 and 34 comprise openings and/or bearing surfaces of any shape that conforms to the bosses. While openings 36 and 38 comprise straight-sided constant diameter cylindrical openings in this example, as another example, openings 36 and 38 may comprise tapered and/or curved diameter openings.

Flow opening 40 through rotary element 30 can be rotated parallel or perpendicular to flow path 42 to open and close rotary valve 10. Flow path 42 may be cylindrical and passes axially through valve 10 when flow opening 40 is open.

Upper and lower trunnion components 26 a, 26 b and 28 a, 28 b are compressed together within body interior 22 and held in place by end connectors 44 and 46 to thereby secure upper and lower bosses 32 and 34 so movement of rotary element 30 is constrained to rotational movement without axial movement along flow path 42. In other words, rotary element 30 is not a so-called floating rotary element.

After valve stem 16 is inserted into valve body 12, rotary element 30 can then be inserted into valve body 12 for locking engagement with valve stem 16. In this embodiment, valve stem 16 comprises an interlocking member that is inserted into mating groove 48 in upper boss 32 to rotationally affix valve stem 16 to upper boss 32 whereby rotation of valve stem 16 results in corresponding rotation of rotary element 30. However, various types of interlocking members may be utilized for rotationally affixing or locking valve stem 16 to upper boss 32 and the shown interlocking member and mating groove 48 is only one example thereof.

During assembly of rotary valve 10, as indicated in FIG. 1 and FIG. 2, end 18 of valve stem 16 is inserted through valve stem opening 14 from interior 22 of valve body 12. Thus, enlarged portion or end 20 or a thrust bearing or the like engages with an interior surface valve body wall 24 to prevent valve stem 16 from being radially outwardly expelled from rotary valve 10 even when rotary valve 10 is under high pressure. Rotary element 30 can then be inserted into valve body 12 whereby valve stem 16 interlocks with slot 48 in upper boss 32 of rotary element 30.

Afterwards, upper and lower split trunnions 26 and 28 can be inserted on opposite sides of valve body 12 to provide that rotary element 30 is trunnion mounted. It will be appreciated that the trunnion/boss mounting can be of many different configurations. In this case, upper and lower split trunnions 26 and 28 are generally rectangular when assembled together and comprise curved outer surfaces 49 and 50. When assembled, openings 36 and 38 are slightly larger in inner diameter than the outer diameter of cylindrical bosses 32 and 34.

Prior to insertion of rotary element 30 into valve body 12, upper and lower thrust washers 52 and 54 may be positioned on upper and lower bosses 32 and 34. Upper and lower rotary trunnion bearings 56 and 58 may also be positioned on upper and lower bosses 32 and 34. Rotary element 30 may then be tilted during insertion so that groove 48 can first engage with valve stem 16 without damaging upper rotary bearing 56.

In this embodiment of rotary valve 10, rotary element 30 is ball shaped. However, the present invention might be utilized with any type of rotary valve, such as ball valves, plug valves, and the like.

In this embodiment, a set of primary seals 72 and secondary seals 74 are utilized to seal between cylindrical flow path 42 through rotary valve 10 and opposite sides of rotary element 30. However, other seals can also be utilized to seal rotary element 30 in accord with the present invention, if desired.

End connectors 44 and 46 of valve 10 secure the trunnions, seals, and other elements within valve body 12 utilizing fasteners, screws, bolts, studs, nuts and/or the like as indicated at 60.

Valve stem 16 also extends through opening 62 in adaptor plate 64, which is utilized and mounted by fasteners, screws, bolts, studs, nuts and/or the like as indicated at 66. However, adaptor plate 64 is not necessary for securing valve stem 16 to valve body 12. Instead, valve stem 16 is inserted into valve body 12 so that enlargement 20, which in this embodiment is on the bottom end of valve stem 16, retains valve stem 16 within valve body 12 without the need for fasteners. In this embodiment, adaptor plate 64 is used for connecting an actuator (not shown) to valve body 12.

During assembly, O-ring seals 73, upper stem seal 70 and thrust washer bearing 68 may be positioned on valve stem 16. Thrust washers 52, 54 and rotary trunnion bearings 56, 58 are placed on upper and lower bosses 32, 34 of rotary element 30. If desired, rotary element 30 can then, be inserted into valve body 12 at an angle so that the connector on valve stem 16 engages groove 48 or other interconnection element on upper boss 32 of rotary element 30. With these components in place within valve body 12, then upper and lower split trunnions 26, 28 can be inserted around upper and lower bosses 32, 34 from opposite sides of valve body 12. Primary 72 and secondary seal 74 assemblies are installed on opposite sides of rotary element 30 and end connectors 44 and 46 are attached to opposite sides of valve body 12. Then actuator adaptor plate 64 can be bolted into place using ferryhead screws 66, or the like.

In general, it will be understood that such terms as “up,” “down,” “vertical,” and the like, are made with reference to the drawings and/or the earth and that the devices may not be arranged in such positions at all times depending on variations in operation, transportation, mounting, and the like. For example, terms such as “upper” and “lower” might also be replaced by terms such as “first” and “second” herein. As well, the drawings are intended to describe the concepts of the invention so that the presently preferred embodiments of the invention will be plainly disclosed to one of skill in the art but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views as desired for easier and quicker understanding or explanation of the invention. One of skill in the art upon reviewing this specification will understand that the relative size and shape of the components may be greatly different from that shown and the invention can still operate in accord with the novel principals taught herein.

Accordingly, the foregoing disclosure and description of the invention is illustrative and explanatory thereof, and it will be appreciated by those skilled in the art, that various changes in the ordering of steps, ranges, interferences, spacings, hardware, and/or attributes and parameters, as well as in the details of the illustrations or combinations of features of the methods and system discussed herein, may be made without departing from the spirit of the invention. 

What is claimed is:
 1. A rotary valve, comprising: a valve body with a first opening on one side of said valve body and a second opening on an opposite side of said valve body, said valve body defining a fluid flow path through said valve body along a valve body axis through said first opening and said second opening of said valve body, said valve body further defining a valve stem opening; a valve stem comprising an enlarged portion, said enlarged portion comprising a diameter greater than said valve stem opening to thereby secure said valve stem within said valve body by limiting radially outward movement of said valve stem with respect to said valve body; a first set of split support elements comprising a first split support element and a second split support element, said first split support element and said second split support element each comprising a continuous curved engagement surface, and when said first set of split support elements are mounted within said valve body then said first set of split support elements form a first circular opening with said continuous curved engagement surfaces with a split between said split support elements; a rotary member with a first extension, said first extension being positioned within said first circular opening defined within said first set of split support elements whereby said first extension is rotatable within said first circular opening, said first extension being interconnectable with said valve stem within said valve body, whereby said rotary member rotates in response to rotation of said valve stem for controlling fluid flow through said fluid flow path through said valve body, said split support sections being mounted within said valve body so that said split is oriented transversely with respect to a valve body axis through said valve body.
 2. The rotary valve of claim 1, further comprising said first split support element being mountable within said valve body through said first opening and said second split support element being mountable within said valve body through said second opening.
 3. The rotary valve of claim 2, further comprising a second set of split support elements which are separately mountable within said valve body, when mounted within said valve body said second set of split support elements defining a second circular opening therethrough, a second extension on said rotary member positioned on an opposite side of said rotary member from said first extension, said second extension being positioned within said second circular opening defined within said second set of split support elements whereby said second extension is rotatable within said second circular opening.
 4. The rotary valve of claim 3, further comprising a first bearing mounted in said first circular opening around said first extension and a second bearing mounted in said second circular opening around said second extension.
 5. The rotary valve of claim 1, further comprising a first end connector which encircles said fluid flow path mounted to said valve body, a second end connector which encircles said fluid flow path mounted to said valve body opposite to said first end connector, said first end connector and said second end connector engaging said first set of split support elements within said valve body.
 6. The rotary valve of claim 1, wherein said rotary member is ball shaped.
 7. The rotary valve of claim 1, further comprising a stem thrust washer mounted on said enlarged portion of said valve stem, said stem thrust washer engaging an inner surface of said valve body.
 8. The rotary valve of claim 1, wherein said first extension is cylindrical.
 9. A method for making a rotary valve, comprising: providing a first opening in a valve body and a second opening on an opposite side of said valve body whereby a flow path through said valve body extends through said first opening and said second opening; inserting a valve stem through a valve stem opening in said valve body and utilizing an enlarged portion of said valve stem which does not pass through said valve stem opening to retain said valve stem within said valve body; mounting a rotary element in said valve body so that said rotary element is operably connected to said valve stem; inserting a first split support element of a first set of split support elements into said first opening; inserting a second split support element of said first set of split support elements into said second opening, whereby after insertion into said valve body said first set of split support elements define a first set of circular surfaces within said valve body for supporting a first portion of said rotary element for rotational movement.
 10. The method of claim 9 further comprising providing that a split between said split support elements is oriented transversely with respect to an axis through said valve body.
 11. The method of claim 9, comprising supporting a second portion of said rotary element for rotational movement by inserting a second set of split support elements into said valve body, said second set of split support elements defining a second set of circular surfaces for supporting said second portion of said rotary element.
 12. The method of claim 11, comprising utilizing a first end connector and a second end connector for securing said first set of split support elements and said second set of split support elements within said valve body.
 13. The method of claim 11, comprising positioning a first continuous circular bearing around said first portion, and positioning a second continuous circular bearing around said second portion.
 14. The method of claim 9, comprising positioning a thrust washer on said enlarged portion of said valve stem to engage an inner surface of said valve body.
 15. A rotary valve, comprising: a valve body, which defines a valve stem opening, a first flow path opening on one side said of said valve body and a second flow path opening on an opposite side of said valve body, said valve body defining a fluid flow path that extends through said valve body, said first flow path opening and said second flow path opening; a valve stem comprising an enlarged portion, said enlarged portion comprising a diameter greater than said valve stem opening to thereby secure said valve stem within said valve body by limiting radially outward movement of said valve stem with respect to said valve body; a rotary member comprising a first portion at a first side of said rotary member; a first set of split support elements comprising a first split support element and a second split support element, said first set of split support elements defining a first circular opening when mounted within said valve body, said first split support element being mountable into said valve body through said first flow path opening and said second split support element being mountable within said valve body through said second flow path opening, said first set of split support elements constraining said first portion of said rotary member for rotational movement, said rotary member being interconnectable with said valve stem within said valve body, whereby said rotary member rotates in response to rotation of said valve stem.
 16. The rotary valve of claim 15, wherein said rotary member comprises a second portion at a second side of said rotary member opposite to said first side, and a second set of split support elements defining a second circular opening, when mounted within said valve body said second set of split support elements constraining said second portion of said rotary member for rotational movement.
 17. The rotary valve of claim 16, wherein said first portion of said rotary member comprises a first cylindrical extension and said second portion of said rotary member comprises a second cylindrical extension.
 18. The rotary valve of claim 15, wherein a split between said first set of split support elements is oriented transversely with respect to an axis through said rotary member. 